2 replies to this topic

[mk=john]

Hi

I need to replace the dynamo on my mini. It will be a new on from minispares, so i dont know if it will be set to positive or negative earth. The car has positive earth.
How do i check the polarity of the dynamo, and whats the method of switching it to positive earth? I heard something about shorting across the terminals. Does anyone know?

Thanks

John

[tiger99]

Simple! Fit the dynamo in the car, but don't connect the leads yet. Connect the battery to the car, earthing the positive terminal. From the live side of the battery, which is negative, make a temporary connection to the small dynamo terminal, marked F, for a second or two, no more. It will spark as you make the connection. Job done, and you can now connect the dynamo into the car's wiring.

You can do it off car, with a battery and pair of jump leads. Battery positive to dynamo body, battery negative to F terminal for a couple of seconds, if more convenient.

If you ever want to go back to negative earth, you do exactly the same, with the battery reversed.

[mk=john]

Thanks!